#include <stdio.h>
#define PI 3.14159265358979323846264338327950288f
int main(void)
{
    int r;
    printf("输入半径: ");
    scanf("%d", &r);
    printf("球体体积：%.2f\n", 4.0f/3.0f * PI * r * r * r);
    return 0;
}